In pirns which are supplied to a double twister, the size of the pirns in the axial direction is larger than the diameter of the yarn layer, and it is generally 320 mm to 460 mm, but it is known that in some pirns, this size is larger or smaller outside this range. In mass production of garments and clothes, pirns having a longer length and a larger diameter are advantageous. However, in the aesthetic use, pirns having a shorter size and a smaller diameter are advantageous. When it is desired to obtain strongly twisted yarns for the aesthetic purpose, if the rotation number of the spindle is the same, the size may be short because a low speed is adopted for manufacture. If the rotation number of the spindle is increased, a small size of a rotary disc is advantageous. Also for this reason, a pirn having a smaller diameter is preferred.
However, in any fields, the length of pirns is inevitably larger than that of cheeses of spun yarns. If the production rate is increased by adopting a so-called two-deck type machine in which spindles are arranged in two lines, since the pirn length is large, the machine height is increased, with the result that a new building becomes necessary for introduction of this machine and the operation adaptability is reduced. If this machine height does not cause a serious disadvantage, as the lay-out of the machine, it is sufficient if a spindle unit, a feed roller and a winding zone are arranged in series in the longitudinal direction. An instance of the conventional technique in which the above problem is solved is shown in FIG. 1. A machine frame 3 is expanded above a spindle unit U vertically mounted on a spindle rail 1, and a guide roller 4, a feed roller 5 and a driving roller 6 for a package PM are arranged on this frame 3. The guide roller 4 is disposed above a yarn supply pirn P to determine the winding angle of the yarn to the feed roller 5.
Since the length of the yarn supply pirn is large as pointed out hereinbefore, it is necessary to prevent the pirn from falling down while twisting is carried out by the rotating spindle. Accordingly, if a wharve 7 is rotated by a belt BL as in the known technique, a rotary disc 8 integrated with the wharve 7 is rotated while a stationary disc 9 placed on the top end of the spindle through bearings BR, that is, the above rotary disc 8, is prevented from rotating by a magnet MG. A guide post 10 is mounted in the central portion of the stationary disc and the pirn P is vertically inserted in this guide post 10. In some case, a tension device or the like is additionally attached to the guide post 10. The size of the guide post 10 is about 2/3 of the size of the pirn P. Since a tension device T and a yarn guide member G are placed on the top end of the pirn, when a new pirn is vertically inserted in the post 10, the pirn should be inserted from the position about 2 times as high as the height thereof. Accordingly, the guide roller 4 should be disposed at a considerably elevated position and the frame should be raised up considerably.
A stationary snail guide SG is disposed just above the pirn. The length between this snail guide SG and an opening 11 of the rotary disc 8 has serious influences on the shape and size of the pirn and the yarn tension, and it is not permissible to locate the snail guide at a much elevated position, that is, the position about 2 times as high as the pirn height, which is necessary for vertical insertion of the pirn. As means for solving this problem, of course, there may be adopted a method in which the snail guide is turned and let to escape when the pirn is inserted in the stationary disc.
Accordingly, even if it is possible to render the snail guide movable, the above-mentioned disadvantage is inevitably caused if the position of the guide roller 4 is elevated.
As means for solving this problem, there has been proposed a method in which a flexible member, for example, a coil spring is used as the guide post 10 and is deformed to the right in FIG. 1 and the pirn is inserted and vertically disposed on the stationary disc. However, this method is defective in that if the rotation number is increased for the high speed operation to 10,000 to 20,000 rpm, stable maintenance of the pirn is difficult by vibrations of the spindle. Furthermore, there has been proposed a method in which the spindle rail 1 is divided in segments for the respective units, the spindle unit as a whole is turned to the right in FIG. 1 and taken out and the spindle unit is returned to the original position after insertion of the pirn. However, this method is defective in that many parts are necessary for taking out the spindle unit and the machine becomes expensive. Furthermore, in case of a two-deck type machine, the travel of a truck for operators in the direction rectangular to the paper face in FIG. 1, that is, in a direction parallel to the spindle rows, on the right side of FIG. 1 is inhibited when the spindle unit is taken out.